Bomb fuze



April 25, 1961 A. s. WILL ET AL BOMB FUZE 2 Sheets-Sheet 1 Filed Sept. 24, 1953 INVENTORS A. s. w|| R. Bl ANCHI (N. c. BUTLER QM. Jm

ATTORNEY April 25, 1961 A. s. w|| ET AL BOMB FUZE Filed Sept. 24, 1355 2 Sheets-Sheet 2 INVENTORS A. S. WILL R. BIANCHI N G. BUTLER ATTORNEYS nos m FUZE Albert S. Will, University Park, Renato Bianchi, Laurel, and Norman C. Butler, Silver Spring, Md, assignors to the United States of America as represented by the Secretary of the Navy Filed Sept. 24, 1953, Ser. No. 382,227

13 Claims. (Cl. l0270.2) (Granted under Title 35, U.S. Code (1952), sec. 266) The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

The present invention relates to a bomb fuze and more particularly to a new and improved electric fuze suitable for use with a low drag fire bomb.

Heretofore, fire bombs employed mechanically actuated fuzes wherein means controlled by the wind driven impeller released the arming means for movement from an initial safe position to an armed position when the impeller made a predetermined number of revolutions during the free flight of the bomb toward a target after being released from an aircraft in flight. It has been found in actual practice, however, that the impeller type arming devices now in use have not proven entirely satisfactory particularly when the bomb is launched from a high-speed aircraft for the reason that the impeller is unable to withstand the high pressure to which it is subjected as the bomb is released from the aircraft and during the air travel thereof toward the target.

The present invention contemplates the provision of a new and improved fuze arrangement for a fire bomb which overcomes all the disadvantages heretofore encountered in prior art fuze devices by providing a new and improved electrically controlled system for arming and firing an incendiary bomb. Moreover, the present invention provides an electric fuze arrangement wherein switch means are employed for maintaining the fuze in a safe condition until the bomb has been released from an aircraft in flight and traveled a predetermined distance therefrom whereupon delayed arming means responsive to an electrical impulse generated as the bomb falls away from the aircraft, delays the arming of the fuze for a predetermined period of time after release of the bomb from the aircraft and in which means responsive to impact of the bomb with the target produces an electrical impulse of suflicient strength to fire an electro-responsive detonator thereby to cause fragmentation of the bomb casing and thus scatter the ignited incendiary mixture over a large target area. Moreover, the voltage generator is adapted to be employed in connection with suitable rectifying means or a diode, whereupon suflicient voltage is generated by the generator as the bomb is released and falls away from the aircraft to break down the diode and fire a time delay device thereby to arm the fuze and charge suitable storage means in time delayed relation with respect to release of the bomb. The charged storage means is adapted to be instantaneously discharged upon impact of the bomb with the target thereby to fire the electroresponsive detonator and explode the bomb. Furthermore, the fuze is provided with means whereby sterilization of the fuze will occur should the bomb strike a target prior to the expiration of the time delay period.

An object of the present invention is the provision of a new and improved electric fuze system for use with a fire bomb.

2,981,190 Patented Apr. 25, 1961 Another object of the invention is to provide a fuze for a fire bomb wherein means actuated by an arming wire maintains the fuze in a safe position until the bomb is released from an aircraft in flight and traveled a predetermined distance therefrom.

Another object of the invention is to provide an electric fuze for an incendiary bomb having delay arming means responsive to an electrical impulse for arming the fuze in time delayed relation with respect to the release of the bomb from an aircraft in flight.

A further object of the invention is to provide an electric fuze for a bomb wherein means including an impulse generating device is adapted to arm the fuze as the bomb is released and moved a predetermined distance from an aircraft in flight.

A still further object of-the invention is the provision of an electric fuze wherein generator means actuated as the bomb is released and falls away from an aircraft in flight is adapted to generate an electrical impulse of suffioient magnitude to fire an explosive delay arming device thereby to delay arming of the fuze for a predetermined period of time after actuation of the generator means.

Still another object of the invention is the provision of an electric fuze wherein means responsive to an electrical impulse generated as the bomb is released and falls away from an aircraft in flight actuates the fuze to an armed position and in which means responsive to impact of the bomb with the target discharges suflicient energy to fire an electroresponsive detonator thereby to cause fragmentation of the bomb casing and scattering of the ignited incendiary mixture over a large target area.

An additional object of the invention resides in the provision of an electric fuze for a fire bomb wherein an explosive element fired in response to an electrical impulse received thereby actuates the fuze to an armed position in time delayed relation with respect to release of the bomb from an aircraft in flight and in which means are provided for causing sterilization of the fuze should the bomb strike a target prior to the expiration of the time delay period.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

Fig. 1 is a schematic view of the fuze arrangement of the present invention illustrating a preferred embodiment thereof in connection with a fire bomb and .a portion or" an aircraft to which the bomb is releasably connected;

Fig. 2 is a diagrammatic representation of the electric fuze arrangement of the device of Fig. 1, in accordance with the present invention;

Fig. 3 is a diagrammatic view of an alternate arrangement of the device of Fig. 1;

Fig. 4 is a diagrammatic view of another arrangement of the device of Fig. 1;

Fig. 5 is a view similar to Fig. 4 illustrating another arrangement of the electric fuze; and

Figs. 6 and 7 are diagrammatic views illustrating still further arrangements of the electric fuze.

Referring now to the accompanying drawings wherein like reference characters designate like parts throughout the several views and more particularly to Fig. 1 thereof the numeral 10 generally indicates a fire bomb comprising a casing 11. The bomb .10 is a conventional type fire bomb and is adapted to be provided with the usual I incendiary mixture such, for example, as gasoline gel or the like. Fire bombs are effectively used against personnel, wooden piers, storage depots, inflammable materials and the like since upon impact they burst and scatter the flaming mixture over a large target area and thus causing considerable damage thereto.

' The'bomb is releasably supported on the bomb, rack 12 by the conventional bomb release means indicated by the reference character 13 whereupon the bomb may,

be released at, will from-an aircraft in flight toward a target by thebombardier, the bomb rack 12 being mounted on the aircraft in the conventional ,manner,

on Fig. l, and indicate'd'by, the reference character 14.

the switches 34 are moved to an open position by the actuating members 33 in predetermined time delayed relation with respect to the firing of the delay elements.

: Furthermore, as the explosive devices 35 are fired by the delay elements therein the primers 40 in the rotors 37 are moved into alignment with the detonators by the I preferably to each wing thereof, one'of which is shown Furthermoraan arming'wire15 is'secured to the rack I in any manner and detachably secured to thefuze thereby to provide means for actuating the arming system of the fuze when the bomb is released and fails a predetermined distance from the aircraft, the, arming cycle of the fuze' being more clearly set forth hereinafter.

The'electric fuze of the'present invention is particularly adapted to initiate the conventional pyrotechnic material arranged within the firebomb thereby to cause fragmentationof the bomb ;upon impact thereof with a" target. The device of the present invention comprises'a. pair of fuz'es' 16-17 which are identical in structure, fuze actuating members 36 in predetermined time delayed relation with respect to the firing of the delay elements. 7 I :When this occurs, the fuzes 16 and 17 are armed. While the delay elements in the explosive devices32-35 provide substantially the same time interval before the ex-v plosivedevices are fired, it will be understood, however,

thatany time sequence between the firing of one with "respect to the other may be provided, if desired. The

aforesaid delay elements are adapted to provide a time delay period of substantially 1.5 seconds thereby, to prov vide sufiicient time to permitthe bornb to travel a safe 'distance from the aircraft before arrning'of the fuzes.

16 being disposed withinthe nose of the bomb and fuze' 17 being disposed within the tail of the bomb, Fig. l.

The aforesaid fuzes are secured to'the bomb casing in With reference to Fig. 2, it will be noted that, the i "aforesaid unit '21 comprises a magnetic impulse generator 23 and a normally closed switch 24,the generator being normally shorted by the switch and operatively:

' connected to the fuzes 1'6--17 by conductors 25--26 and plug and jack connections 27- 28 and thus by this an rangement the unit may be readily attached andidetached from the bomb, if desired. The generator 23 comprises a coil 29 and a movable magnet or core 31 fixed to the open position and the arming wire is released therefrom prior to the movement of the magnetic element 31 through the coil 29 in response to the movement of the bomb away from the aircraft after being released therefrom. i

As shown on Fig. 2, each fuze comprises a time delay explosive element 32 having an actuating member 33 secured thereto and to a normally closed switch 34, and a second time delay explosive device 35 having an actuating member 36 secured thereto and to an arming rotor 37, an explosive charge or primer mounted in the rotor, a firing circuit 38, an electroresponsive detonator 39, and a magnetic inertia generator 41 included in the firing circuit and comprising a movable magnetic core 42 and a coil 43.

As shown on Fig. 2, the aforesaid explosive devices 32 and 35 are connected in parallel across conductors 44 45, conductor 44 being connected to one terminal of the coil 29 by way of connector 28 and conductor 26, and conductor being connected to the other terminal of the coil 29 by way of connector 27 and conductor 25 and thus establishing an initiating circuit from the impulse generator 23 to the explosive switch devices 32 and 35. It will be noted, however, that the generator 23 is shorted by the normally closed switch 24 and the generators 41 are shorted by the normally closed switch 34. Furthermore, the arming rotors 37 are in an initial safe position with explosive charges 40 therein being out of alignment with the detonators 39. Thus with the aforesaid elements and component parts of the fuzes in the aforesaid position premature firing thereof is prevented.

The explosive devices 32-35 are provided with suitable delay elements adapted to be fired in response to an electrical impulse received thereby from the generator 23 as the generator is operated as the bomb is released from the aircraft and falls away therefrom. As the explosive devices 32 are fired by the delay element therein,

i arming Wire 15 which wire is detachably secured to the switch in such a manner that the switch is actuated to an I In operation of the aforesaid device it will be understood that upon release of the bomb from an aircraft in flight the switch 24 is moved to an open position by the t arming wire 15 prior to operation of the impulse generator 23. As the bomb, falls away from the aircraft, the switch 24is opened thereby unshorting the initiating cir-' cuit between the generator 23 and explosive devices 32- 35. Upon further movementoi the bomb from the aircraft the arming was is released from the now open I switch 24-and the magnetic, element 31, of the generator 23 is moved through coil 29'by the arming wire'lS and in response to such movement of the core with re, spect to the coil an electrical. impulse of sufiicient strength is, generated therein to fire the delay elements arranged within the explosive devices 32 and 35.v When a predetermined period of time has elapsed, the expiosive devices.32--35 arefired by the delay elements asso ciated therewith. Upon firing, of the devices 32 the acmating member'33 movesthe, switches 34 to an open position thereby unshorting the detonators 39 and providing a firing circuit from the inertia magnetic generators 41to the detonators '39. Furthermore, upon firing of the devices 35 the actuating members 36 move the I arming rotors 37 a sufiicient amount to align the primers 40 with the detonators 39. Thus the fuzes are armed and upon impact of the bomb with a target, the magnetic element 42 is moved through the coil 43 and in response to such movement sufficient energy is generated in the coil to fire the detonators 39 thereby to cause fragmcntation of the bomb casing and scatter the ignited incendiary mixture over a large target area. v

In the arrangement of Fig. 3, it will be noted that the impulse generating means and the shorting means are the same as shown on Fig. 2 and also function in like manner to the arrangement of Fig. 1. The fuze 46 of Fig. 3 is provided with a cold cathode gas diode 47, an explosive delay device 48, similar to the explosive device 32, and a condenser 49 which are included in an initiating circuit 51 normally shorted by the switch 24. Furthermore, the explosive delay device 48 is provided with a resistor 52 which is disposed between the diode 47 and the condenser 49 and in parallel with the bridge element of the conventional delay squib of the explosive device, ;he lpurpose of whichwill be hereinafter more clearly set It will be noted in. the arrangement of Fig. 3, that the explosive switch 48 is arranged within the firing circuit 50 and provided with an actuating member 53 operative- It will be understood that in the aforesaid arrangement the explosive device 48 is fired and the condenser 49 is charged after the switch 24 has been actuated to an open position and the coil 29 has generated sufiicient energy to cause the diode 47 to break down in response to movement of the magnetic element therethrough.

By the use of the resistor 52, an electrical path between the generator and condenser will be established should the bridge element of the delay squib fuse or burn prematurely thereby to ensure charging of the condenser 49. Furthermore, the switch elements 54, 55 and 56 mounted on the actuating member 53 maintain the fuze in an initial safe position and are adapted to arm the fuze as the member 53 is moved a predetermined amount by the explosive device as the device is fired by the delay element thereof, the time interval between firing of the delay element and operation of the actuating member 53 by the explosive device being, by way of example, substantially 1.5 seconds.

It will be noted that when the fuze is in a safe condition, the switch element 54 is in engagement with contacts 61, switch element 56 is normally out of engagement with contacts 62 and switch element 55 is normally in engagement with contacts 63. By the aforesaid switch arrangement, the condenser 49 is normally shorted by the switch 54 and thus should the impact switch 59 be actuated to a closed position prior to the expiration of the aforesaid time delay period the condenser will be discharged through switches 59 and 54. Furthermore, switch 56 and contacts 62 interrupt the firing circuit to the primer 57 and switch 55 and contacts 63 maintained the primer 57 shorted. Moreover, the firing circuit 50 to the primer 57 remains interrupted and the primer remains shorted until the explosive device has been fired. When this occurs, switch element 54 is moved out of engagement with contacts 61, switch element 56 is moved into engagement with contacts 62, switch element 55 is moved out of engagement with contacts 63 and the arming rotor 58 is moved to an armed position. Thus the fuze is armed, however, the energy stored in the condenser 49 will not be discharged therefrom through the primer 57 until the impact switch 59 is actuated to a closed position in response to impact of the bomb with the target. When this occurs, the energy in the condenser 49.

is discharged through the primer 57 thereby to fire the primer, the flash from the primer fires the explosive train arranged within the arming rotor 58 and thus the bomb is exploded and the ignited incendiary'mixture is scattered over the target area.

In the arrangement illustrated on Fig. 4, the fuze is generally indicated by the reference character 64 and o is provided with an impulse generator 65'comprising a movable inertial magnetic element 66 and a coil 67. The movable element 66 is disposed within a recess 68 formed in a suitable receptacle 69 carried by the bomb and maintained within the recess and detachably secured to the receptacle by the arming wire 71. The movable element is adapted to be forcibly ejected from the recess and through the coil by a spring 70 as the bomb is released from the aircraft and the arming wire 71 is withdrawn from the receptacle in response to movement of the bomb away from the aircraft. As the magnetic element 66 moves through the coil 67, sufiicient voltage is generated in the coil to fire the pyrotechnic delay device 72 which functions in the same manner as the aforesaid explosive devices shown on Figs. 2 and 3. When the explosive device 72 is fired, the actuating member 73 thereof moves the switch elements 74, 75 and 76 a sufficient amount to interrupt the circuit between explosive device 72 and the generator 65, to connect the generator in series with the primer 77 and impact switch 79, to unshort the primer; and to move the arming rotor 78 from an initial safe position to an armed position thereby arming the fuze. In this arrangement it will be understood that the genorator 65 is also adapted to generate a voltage impulse in the coil of sufiicient energy to fire the primer 77 as the movable inertial element 66 in response to the force I of target impact overcomes the force of spring 70 and is moved therethrough whereupon the impact switch 79 is closed in response to impact of the 'bomb with the target thereby to function the bomb on the target.

The fuze system of Fig. 5 comprises a dash pot arrangement generally indicated by the reference character 81 and comprising a casing 82 having a piston 83 movably arranged therein. The piston comprises a head 84 disposed within a chamber 85 formed in the casing 82 and a stem 86 slidably arranged within the casing and releasably locked thereto by an arming wire 87. An arming slider 88 is slidably arranged within the casing 82 for movement from an initial safe position to an armed position when released, the slider being maintained in an initial safe position by the stem 86. The slider 88 is provided with an explosive element 89 normally out of alignment with the primer 91 and adapted to be moved into alignment therewith by spring 92 when the arming wire is withdrawn from the stem 86 and the piston is moved by the spring 93 an amount suflicient to disengage the stem from the slider. 1

The movement of the piston to a release position by spring 93 is retarded by the fluid in the chamber and since the head 84 is provided with a minute bleeder opening 94, moving of the piston to a release position will be in the neighborhood of 1.5 seconds after release of the bomb from the aircraft thereby delaying arming of the fuze until the bomb has travelled a predetermined distance from the aircraft. Furthermore, in this arrangement, it will be noted that the primer 91 is shorted by a normally closed switch 95 maintained in a closed position by the stem 86 of the piston and adapted to be moved to an open position when the piston is moved to the aforesaid release position When this occurs a firing circuit from the magnetic inertia generator 23 to the primer 91 is established and thus upon impact of the bomb with the target, the primer is fired in response to an electrical impulse generated by the generator. 7

In the arrangement of Fig. 6, the fuze is generally indicated by the reference character 96 and comprises an RC time delay circuit for delaying the arming of the fuze in lieu of the pyrotechnic delay devices heretofore shown and described. The circuit includes a diode 97, a storage condenser 98, a switch 99, a resistor 101, a firingcondenser 102, an impact firing switch 103, and a primer 104. In like manner to Figs. 2 and 3, the magnetic generator 23 and shorting switch 24 are employed with the device of Fig. 6 and are adapted to be actuated by the arming wire 15.

It will be understood, however, that when the switch 1 24 and generator 23 are operated sufl'icient voltage is generated thereby to cause the diode to break down and thus the storage condenser 98 is charged, which in turn charges firing condenser 102 by way of resistor 101 when a predetermined period of time has elapsed. Moreover, the voltage increase on the firing condenser 102 is sufficient to fire the primer in substantially 1.5 seconds. However, should impact occur prior to the aforesaid time interval, voltage on the firing condenser will be insufficient to fire the primer and the voltage on the storage condenser 98 will be discharged by way of the impact switch 99 which prevents further build up of the charge on the firing condenser 102. However, at the expiration of the 1.5 seconds delay period the voltage on the firing condenser has increased to an amount suificient to fire the primer 104. Thus, upon impact of the bomb with the target impact switch 103 is actuated to a closed position and the condenser 102 is discharged through the switch and the primer 104 whereupon the bomb is exploded and the ignited incendiary mixture thereof is scattered over the target area. i

The arrangement of Fig. 7 is similar to the device of Fig. 6 and in like manner is functioned by an electrical 7 impulse developed as the generator 23 is actuated and the switch24 has been moved to an open positlon. In this arrangement, however, additional means are provided for delaying the charging of the firing condenser 102 and include a timing condenser 105 and a cold cathode gas diode 106 which are disposed between the timing condenser 105 and the firing condenser 102. Furthermore, with the cold cathode diode 106 arranged within the circuit as shown, the firing condenser 102 is isolated from the timing condenser 105 and thus eliminating the need for accurate adjustment of the primer firing energy. Moreover, when the generator 23 is operated sufficient energy is developed thereby to break down the cold cathode diodes 97 and 106 and to charge the condenser 98, 105, and 102 whereupon the firing condenser 102 ultimately attains a voltage of suificient magnitude to fire the primer 104. Thus upon impact of the bomb with a target the firing condenser 102 is discharged through the detonator 104 by way of now closed impact switch 103 thereby to fire the detonator and explode the bomb on the target.

From the foregoing, it will be apparent that a new and improved electric fuze has been devised for use in a fire bomb wherein means responsive to an electrical impulse generated as the bomb is released and falls away from an aircraft causes the fuze to be armed in time delayed relation with respect to release thereof, and in which means responsive to impact of the bomb with a target causes suflicient electrical energy to be discharged therefrom to fire an electroresponsive detonator instantaneously thereby to explode the bomb and scatter the ignited incendiary mixture over a large target area. Furthermore, the fuze device provides new and improved means including a normally short circuit arrangement for maintaining the bomb in a safe condition until the bomb has been released from an aircraft in flight, and in which means responsive to a sudden impact prevents firing of an 'electroresponsive detonator until a predetermined period of time has eiapsed after release of the bomb from the aircraft.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. In a bomb adapted to be released from an aircraft in flight comprising a fuze, means for maintaining the fuze in a safe condition until the bomb is released from said aircraft, means responsive to an electrical impulse for arming said fuze in time delayed relation with respect to the release of the bomb from said aircraft, generating means operated by the movement of said bomb away from said aircraft for generating said impulse, an electroresponsive detonator in said fuze, and means responsive to impact of the bomb with a target for generating suflicient electrical energy to fire said detonator thereby to explode thebomb.

2. In a bomb adapted to be released from an aircraft in flight comprising a fuze, an electrical circuit in said fuze, a normally closed switch included in said circuit for maintaining the fuze in a safe condition until said switch is actuated to an open position, means for actuating said switch to said open position in response to movement of the bomb away from said aircraft after release of the bomb therefrom, explosive means included in the circuit and fired in response to an electrical impulse when said switch is in said open position, a magnetic impulse generator in electrical communication with said explosive means when said switch is in said open position for generating said electrical impulse in response to said movement of said bomb, a normally shorted electroresponsive detonator included in said circuit, means operatively connected to said explosive means for rendering the detona- 8 tor efiective as the explosive means is fired, and means including a device responsive to impact of the bomb with. a target for generating suflicient electrical energy to fire the detonator thereby to explode the bomb.

3. An electric fuze for use in a fire bomb adapted to be released from an aircraft in flight comprising a normally shorted electrical circuit, means for rendering said circuit eflective as the bomb is released and falls away from said aircraft, a magnetic impulse generator included in said circuit for generating an electrical inpulse when said circuit is rendered eflective and the bomb has travelled a predetermined distance from said aircraft, explosive means fired in response to said impulse for arming said fuze, means including an impact responsive magnetic generator for generating an electrical impulse as the bomb strikes a target, and an electroresponsive detonator fired by said impulse'for exploding the bomb.

4-. An electric fuze for use in a fire bomb adapted to be released from an aircraft in flight toward a target comprising a normally shortedelectrical circuit, switch means for rendering said circuit effective as the switch means is actuated, meansfor actuating said switch means as the bomb falls away from said aircraft, a magnetic impulse generator connected to said actuating means and operated thereby for generating an electrical impulse in time delay relation with respect to the actuation of said switch means, an explosive device operatively connected to said generator, means including a delay element disposed within said explosive device and fired by said impulse for arming the fuze in time delay relation with respect to the firing of said delay element, an electroresponsive detonator in said fuze, means operatively connected to said detonator for rendering said detonator effective upon impact of the bomb with said target, and a magnetic voltage generator responsive to said impact for generating a voltage of sufiicient strength to fire said detonator thereby to explode said bomb.

5. An electric fuze for use in a fire bomb adapted to be released from an aircraft in flight toward a target comprising a normally shorted initiating circuit, switch means for rendering said. circuit effective as the switch means is actuated, .means secured to said aircraft and releasably attached to said switch means for actuating the switch means and thereafter releasing said switch means as the bomb falls away from the aircraft, a magnetic impulse generator included in said circuit and connected to said actuating means for generating an electrical impulse a predetermined period of time after actuating of said switch means, an explosive device included in said circuit, a delay element disposed within said explosive device and fired by said impulse for firing said explosive device in time delayed relation with respect to the firing of said delay element, a normally shorted firing circuit, means connected to said explosive device and actuated thereby as the explosive device is fired for rendering said firing circuit effective, an electroresponsive detonator arranged within said firing circuit, and a magnetic voltage generator responsive to impact of the bomb with said target for generating a voltage suflicient to fire said detonator thereby to explode the bomb on the target.

6. An electric fuze for use in a fire bomb adapted to be released from an aircraft in flight toward a target comprising a normally shorted initiating circuit and a normally shorted firing circuit, means for rendering said initiating circuit effective as the bomb is released from said aircraft, explosive means fired in response to an electrical impulse received thereby for rendering said firing circuit eflective, impulse generating means included in said initiating circuit for generating said impulse, an electroresponsive detonator in said firing circuit, and means including a magnetic voltage generator for generating a voltage of suflicient strength to fire said detonator thereby to explode the bomb.

7. In an aircraft launched electric bomb fuze, an electroresponsive detonator, a charging circuit, condenser and explode the bomb.

storage means in said charging circuit, a magnetic impulse generator having a stationary coil and a core movable therethrough upon release of the bomb from the aircraft for developing an impulse included in said charging circuit for charging said storage means, means responsive to said impulsefor arming said fuze, means for interrupting said charging circuit when the charge on said condenser has reached a predetermined value, and means for discharging said storage means through the detonator upon impact of the bomb with a target thereby to fire the detonator and explode the bomb.

8. In an electric bomb fuze of the character described,

'an' electrical circuit, storage means in said circuit, a

magnetic impulse generator included in said circuit for developing an electrical impulse for charging said storage means, means included in said circuit and rendered effective when the charge on said storage means has reached a predetermined value for interrupting said circuit and maintaining a charge on the storage means, means including an explosive device included in said circuit for arming said fuze as the deviceis fired in response to said impulse, an electroresponsive detonator, and impact responsive means for discharging said storage means through the detonator upon impact of the bomb with a target thereby to fire the detonator and explode the bomb.

9. An electric fuze of the character described for use ,in a fire bomb comprising a charging circuit, storage device is fired in response to said impulse, an electroresponsive detonator connected in said firing circuit for electrical communication with said storage means when the switch has been actuated to said closed position, and a normally open inertia switch in said firing circuit for discharging said storage means through the detonator as the switch is moved to a, closed position upon impact of the bomb with a target-thereby to fire said detonator 10. In an electrical fuze for arming an airborne fire bomb in time delayed relation withrespect to the resition, means for actuating said switch in response to movement of the bomb away from said aircraft after 10 means, a firing circuit in electrical communication with said storage condenser when the fuze has been armed, an electroresponsive detonator connected in said firing circuit for electrical communication with said firing condenser, and a normally open inertia switch disposed withing said firing circuit for discharging said condenser through said detonator as the switch is operated to a closed position thereby to fire said detonator and explode the bomb.

and coil elements, said core element being actuated into proximate relationship with said coil element asthe bomb is released from said aircraft for generating sufiicient electrical energy to charge said storage condenser, said firing condenser being gradually charged by said storage condenser when the charge on said storage condenser has reached a' predetermined value, an electroresponsive detonator connected to said firing condenser, and means responsive to impactof the bomb with a target for discharging said firing condenser through said detonator thereby to fire the detonator and explode the bomb.

12.'An electric fuze of the characterdescribed for use in a fire bomb comprising a charging circuit, storage means in said circuit, amagnetic impulse generator in said circuit and including cooperatively arranged coil and core elements for charging said storage means with a predetermined amount of electrical energy, means included. in said circuit and rendered efiective when the charge on the storage device has reached a predetermined value for interrupting said charging circuit and maintaining a charge on said storage mean-s, a time delay circuit, a firing condenser included in said time delay circuit and charged by said storage condenser when the charge thereon has reached said predetermined value, an electroresponsive detonator connected to said firing condenser, and means responsive to impact of the bomb with a target for discharging said firing condenser through said detonator thereby to fire the detonator and explode the bomb.

13. In a bomb adapted to be released from an aircraft in flight comprising a magnetic impulse generator includ having energy storage means therein and rendered efiece tive by said impulse for arming the bomb in time delayed lease ofthe bomb from the holding means comprising'ja normally shorted charging circuit,- switch means for 1 relation with respect to the release of the bomb frorn the aircraft, anelectroresponsive detonator,..and an impact responsivedevice operatively connected to said storage.

' means and detonatorffor' discharging saidenergy from being released by said holding means, a condenser in .said'circuit, a magnetic impulse generator in electrical communication with said condenser as said switch means is actuated to said open position forgenerating suflicient electrical energyto charge said condenser as the gene'n; ator is operated bysaid actuating means, means rendered "If efl ective when the charge on the condenser has reached a predetermined value forinterrupting said charging circuit, means responsive to theenergy discharged from said condenser for arming the fuze in time delayed-relation with respect to the release of the bomb by said holding the storage means through. the detonator upon impact of the bomb with a target thereby-to fire said detonator and explode the bomb. 7

7 References Cited in the at or this patent UNITED STATES PATENTS 1,623,475 Hammond Apr. 5, 1,927

1,711,693 Ruhlemann' May 7, 1929 7 e s 1,739,921 Schuler et a1 Dec. 17,1929 1,841,983 R-uhlemann -I lan. 19, 1932 i FOREIGN. PATENIS W I 525,333 Great Britain Au 127, 1940 

